Spatio-Temporal Analysis of Meteorological Elements in the North China District of China during 1960–2015

Abstract

Abstract:The North China District (NCD) is one of the main grain production regions in China. The double cropping system of irrigation has been leading to the groundwater table decline at the speed of 1-2 m per year. Climate change leads to uncertainty surrounding the future of the NCD agricultural system, which will have great effects on crop yields and crop water demands. In this research, the Meteorological dataset from 54 weather station sites over the period 1960-2015 were collected to quantify the long-term spatial and temporal trends of meteorological data, including daily minimum temperature (T min ), maximum temperature (T max ), precipitation, solar radiation, reference evapotranspiration (ET 0 ), and aridity index (AI). The results show that the long-term wheat and maize growing season and annual average air temperatures (T min and T max ) showed strong north to south increasing trends throughout the NCD. The average annual precipitation was 632.9 mm across the NCD, more than 70% of which was concentrated in the maize growing season. The regional average annual ET 0 was 1026.1 mm, which was 531.2 and 497.4 mm for the wheat and maize growing season, respectively. The regional precipitation decreased from northwest to southeast in each growing season and annual timescale. The funnel areas have lower precipitation and higher ET 0 than the regional average, which may lead to the mining of the groundwater funnel area. The regional average annual AI is 0.63, which lies in the humid class. For temporal analysis, the regional average trends in annual T min , T max , solar radiation, ET 0 , precipitation, and AI were 0.37 • C/10a, 0.15 • C/10a, −0.28 MJ/day/m 2 /10a, −2.98 mm/10a, −12.04 mm/10a, and 0.005/10a, respectively. The increasing trend of temperature and the decreasing trend of solar radiation may have a negative effect on the regional food security. The funnel area AI showed a significant increasing trend for the winter wheat growing season and a decreasing trend for maize, which indicated that more irrigation will be needed for the maize growing season and the winter fallow policy may lead to the increasing trend precipitation being wasted. Analyzing the growing season and the annual meteorological elements of the spatiotemporal trends can help us better understand the influence of climate change on the natural resources and agricultural development in both the past and the future, and will provide us with invaluable information for the modification of cropping patterns to protect the regional and national water and food security.

Assessment of winter wheat water‐saving potential in the groundwater overexploitation district of the North China Plain

“…Similar results were found by Ti et al. (). Thus, the water balance in the GOD is not suitable for winter wheat growth, and more groundwater in this area needs to be exploited for agricultural production.…”

“…Our results showed that precipitation during the winter wheat growing season in the GOD was lower than that in other areas, while the ETc and ETaw were higher, especially in the DOA and SOA. Similar results were found by Ti et al (2018). Thus, the water balance in the GOD is not suitable for winter wheat growth, and more groundwater in this area needs to be exploited for agricultural production.…”

“…The region is located in the middle latitudes between 30° and 43° N, which is a monsoon climate zone. The annual average temperature is 8 to 15°C, and the annual sunshine duration is 2800 h. The annual precipitation is 500 to 900 mm, mostly concentrated in June to August (Ti et al., ). The cropping system in this area is winter wheat–summer maize double cropping rotation, which has been sustained for many years (Zhao et al., ).…”

“…Both indexes are widely used in the evaluation of agricultural water usage. There are many equations to estimate ETc (Priestley & Taylor, ; Ti et al., ; Zhou et al., ). In this study, we used the Food and Agriculture Organization (FAO) Penman–Monteith equation, which has been widely used throughout the world.…”

“…Both indexes are widely used in the evaluation of agricultural water usage. There are many equations to estimate ETc (Priestley & Taylor, 1972;Ti et al, 2018;Zhou et al, 2006). In this study, we used the Food and Agriculture Organization (FAO) F I G U R E 1 Location of the North China Plain (NCP); the black points represent the weather station sites, and different colors show the different types of groundwater overexploitation districts, including the deep overexploitation area, shallow overexploitation area, and mixed area Penman-Monteith equation, which has been widely used throughout the world.…”